Do blind people hear better?
Authors: Carina J. Sabourin, Yaser Merrikhi, Stephen G. Lomber
Journal: Trends in Cognitive Sciences (2022)

The auditory system develops atypically in the absence of visual input, resulting in perceptual differences and the recruitment of brain areas beyond the auditory cortex to perform auditory functions.Enhancements are restricted to specific auditory functions in the early blind. How might compensatory plasticity be subserving these perceptual differences?In the early blind, many visual areas appear to preserve their functional specificity following blindness despite adapting to auditory input, suggesting that the cortex is organized based on specific functions rather than by sensory input.We posed the question: do blind people hear better? If so, what are the underlying neural substrates and cortical mechanisms subserving these perceptual differences? And finally, what do the revealed insights mean for our understanding of cortical plasticity and organization in general? For centuries, anecdotal evidence such as the perfect pitch of the blind piano tuner or blind musician has supported the notion that individuals who have lost their sight early in life have superior hearing abilities compared with sighted people. Recently, auditory psychophysical and functional imaging studies have identified that specific auditory enhancements in the early blind can be linked to activation in extrastriate visual cortex, suggesting crossmodal plasticity. Furthermore, the nature of the sensory reorganization in occipital cortex supports the concept of a task-based functional cartography for the cerebral cortex rather than a sensory-based organization. In total, studies of early-blind individuals provide valuable insights into mechanisms of cortical plasticity and principles of cerebral organization. For centuries, anecdotal evidence such as the perfect pitch of the blind piano tuner or blind musician has supported the notion that individuals who have lost their sight early in life have superior hearing abilities compared with sighted people. Recently, auditory psychophysical and functional imaging studies have identified that specific auditory enhancements in the early blind can be linked to activation in extrastriate visual cortex, suggesting crossmodal plasticity. Furthermore, the nature of the sensory reorganization in occipital cortex supports the concept of a task-based functional cartography for the cerebral cortex rather than a sensory-based organization. In total, studies of early-blind individuals provide valuable insights into mechanisms of cortical plasticity and principles of cerebral organization. Following early sensory deprivation, the brain demonstrates an ability to structurally and functionally reorganize to optimally compensate for the lost modality. This reorganization provokes the enhancement of specific visual abilities in the deaf [1.Bavelier D. et al.Do deaf people see better?.Trends Cogn. Sci. 2006; 10: 512-518Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar]. Similar to auditory deprivation, the wealth of unused cortical space present in the visually deprived brain affords opportunities for compensatory plasticity (see Glossary) as well as augmented crossmodal plasticity to occur [2.Rauschecker J.P. Compensatory plasticity and sensory substitution in the cerebral cortex.Trends Neurosci. 1995; 18: 36-43Abstract Full Text PDF PubMed Scopus (435) Google Scholar, 3.Rauschecker J.P. Kniepert U. Auditory localization behaviour in visually deprived cats.Eur. J. Neurosci. 1994; 6: 149-160Crossref PubMed Scopus (0) Google Scholar, 4.Rauschecker J.P. Korte M. Auditory compensation for early blindness in cat cerebral cortex.J. Neurosci. 1993; 13: 4538-4548Crossref PubMed Google Scholar]. Following vision loss, crossmodal recruitment of auditory functions in visual cortex maintains the proto-organization of the visual system, suggesting that insights gleaned from blind individuals can be extended to other forms of sensory loss and are indicative of general plasticity mechanisms. It has long been recognized that the input of a single sensory modality significantly shapes the development of brain structure and function. Loss of sensory input before a critical period, a time of heightened sensitivity to a specific sensory input, augments the degree of cortical reorganization. This was first recognized when profound cytoarchitectural changes were observed in developing cats that lacked monocular visual input for only a few days, while adult cats with similar limited monocular input for over a year experienced no measurable long-term changes [5.Hubel D.H. Wiesel T.N. The period of susceptibility to the physiological effects of unilateral eye closure in kittens.J. Physiol. 1970; 206: 419-436Crossref PubMed Google Scholar]. Lack of sensory input can prolong the duration of the critical period as the circuit remains in a mostly inactivated state [6.Chung S. et al.Peripheral sensory deprivation restores critical-period-like plasticity to adult somatosensory thalamocortical inputs.Cell Rep. 2017; 19: 2707-2717Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar,7.Mowery T.M. et al.Transient hearing loss within a critical period causes persistent changes to cellular properties in adult auditory cortex.Cereb. Cortex. 2015; 25: 2083-2094Crossref PubMed Scopus (51) Google Scholar], averting cytoarchitectural changes. Unlike individuals with late-onset blindness, people with vision loss during critical periods are more prone to visual cortex plasticity, and cortical reorganization is not limited by visual experience during visual critical periods. Previous work has used the blind as a model of cortical plasticity to explore multisensory processing and the proto-organization of the human cerebrum. This line of investigation has engendered new theories and changed how the development and organization of the cerebrum are understood (for reviews, see [8.Bedny M. Evidence from blindness for a cognitively pluripotent cortex.Trends Cogn. Sci. 2017; 21: 637-648Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar, 9.Heimler B. et al.Origins of task-specific sensory-independent organization in the visual and auditory brain: neuroscience evidence, open questions and clinical implications.Curr. Opin. Neurobiol. 2015; 35: 169-177Crossref PubMed Scopus (55) Google Scholar, 10.Hötting K. Röder B. Auditory and auditory-tactile processing in congenitally blind humans.Hear. Res. 2009; 258: 165-174Crossref PubMed Scopus (64) Google Scholar, 11.Reich L. et al.The brain as a flexible task machine: implications for visual rehabilitation using noninvasive vs. invasive approaches.Curr. Opin. Neurol. 2012; 25: 86-95Crossref PubMed Scopus (62) Google Scholar, 12.Ricciardi E. et al.Mind the blind brain to understand the sighted one! Is there a supramodal cortical functional architecture?.Neurosci. Biobehav. Rev. 2014; 41: 64-77Crossref PubMed Scopus (97) Google Scholar]). However, the specific acoustic processes that are amplified in blind individuals remain unclear, and uncertainty exists regarding how the visually deprived cortex allows functional changes to manifest. These questions may be attributable to the heterogeneous nature of blindness etiology. Here, we synthesize the available psychophysical and neuroimaging literature to critically examine auditory function in the blind and the possible neural substrates and mechanisms subserving those functions. We asked three simple questions: (i) do the blind hear better? (ii) if so, which brain regions contribute to these perceptual enhancements? and (iii) what principles of cerebral organization can be gleaned from these studies? Critical periods for processes like depth perception [13.Gibson E.J. Walk R.D. The "visual cliff.".Sci. Am. 1960; 202: 64-71Crossref PubMed Google Scholar], stereopsis [14.Fawcett S.L. et al.The critical period for susceptibility of human stereopsis.Investig. Ophthalmol. Vis. Sci. 2005; 46: 521-525Crossref PubMed Scopus (0) Google Scholar], and synaptic development [15.Johnson M.H. Developmental Cognitive Neuroscience. Blackwell Publishers, 1997Google Scholar] are thought to end before or around age 5 in humans. As such, early and late blindness are often classified as onset before age 5. The impact of compensatory plasticity on auditory cognition in the congenitally and early blind is well documented, which is not the case for the late blind. As such, we largely restrict our discussion to individuals who were born or became blind before age 5, henceforth referred to as the early blind, with peripheral defects and little or no light perception, due to damage anterior to the optic chiasm. Focusing on these impairments reduces the potential for neurological damage and residual vision (like sight in a specific hemifield or the perception of form which greatly impacts auditory cognition, especially spatial processing [16.Papadopoulos K. et al.The impact of residual vision in spatial skills of individuals with visual impairments.J. Spec. Ed. 2011; 45: 118-127Crossref Scopus (17) Google Scholar]) to act as confounds. The intended outcome of this analysis is to, after controlling for the necessary confounds, determine if early-blind individuals possess superior auditory abilities and how their cerebrum engendered these enhancements. The visual processing abilities of the early blind have been extensively investigated through various psychophysical studies. A comparison of the performance of early-blind and sighted individuals suggests that rather than general auditory processing enhancements, more specific improvements in auditory feature, spatial, and language processing occur. Some improvements are accompanied by a deficit in another auditory function in the same domain, suggesting a trade-off between these two functions. Early-blind subjects demonstrate comparable performance to sighted controls for many low-level sensory tasks, particularly for acoustic feature processing (Table 1) [17.Trudeau-Fisette P. et al.Compensations to auditory feedback perturbations in congenitally blind and sighted speakers: acoustic and articulatory data.PLoS One. 2017; 12: 1-20Crossref Scopus (6) Google Scholar, 18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar, 19.Gandhi P.H. et al.A comparative study of simple auditory reaction time in blind (congenitally) and sighted subjects.Indian J. Psychol. Med. 2013; 35: 273-277Crossref PubMed Scopus (8) Google Scholar]. Similarly, individuals with early- and late-onset blindness exhibit similar sensitivity thresholds for phoneme and sound intensity discrimination, suggesting that visual input during development may not be crucial for discrimination processing in these domains [18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar]. For some processes, such as temporal processing [20.Campus C. et al.Stronger responses in the visual cortex of sighted compared to blind individuals during auditory space representation.Sci. Rep. 2019; 9: 1935Crossref PubMed Scopus (15) Google Scholar, 21.Muchnik C. et al.Central auditory skills in blind and sighted subjects.Scand. Audiol. 1991; 20: 19-23Crossref PubMed Google Scholar, 22.Vercillo T. et al.Early visual deprivation severely compromises the auditory sense of space in congenitally blind children.Dev. Psychol. 2016; 52: 847-853Crossref PubMed Scopus (54) Google Scholar], it is unclear whether the blind possess an advantage (Table 1). By contrast, more efficient frequency processing was observed for both frequency selectivity (Figure 1A ) [23.Röder B. et al.Effects of interstimulus interval on auditory event-related potentials in congenitally blind and normally sighted humans.Neurosci. Lett. 1999; 264: 53-56Crossref PubMed Scopus (81) Google Scholar,24.Boroujeni F.M. et al.Comparison of auditory stream segregation in sighted and early blind individuals.Neurosci. Lett. 2017; 638: 218-221Crossref PubMed Scopus (1) Google Scholar] and discrimination tasks (Figure 1B) [18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar,25.Rokem A. Ahissar M. Interactions of cognitive and auditory abilities in congenitally blind individuals.Neuropsychologia. 2009; 47: 843-848Crossref PubMed Scopus (0) Google Scholar, 26.Gougoux F. et al.Pitch discrimination in the early blind.Nature. 2004; 430: 309Crossref PubMed Google Scholar, 27.Wan C.Y. et al.Early but not late-blindness leads to enhanced auditory perception.Neuropsychologia. 2010; 48: 344-348Crossref PubMed Scopus (0) Google Scholar]. Improved frequency perception cannot be attributed solely to superior musical abilities, as these findings have been replicated in studies that controlled for musical ability [18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar,25.Rokem A. Ahissar M. Interactions of cognitive and auditory abilities in congenitally blind individuals.Neuropsychologia. 2009; 47: 843-848Crossref PubMed Scopus (0) Google Scholar]. However, the impact of vision during development on frequency processing is less clear because similar superior frequency discrimination was identified in both early- and late-blind subjects [18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar,27.Wan C.Y. et al.Early but not late-blindness leads to enhanced auditory perception.Neuropsychologia. 2010; 48: 344-348Crossref PubMed Scopus (0) Google Scholar,28.Collignon O. et al.Impact of blindness onset on the functional organization and the connectivity of the occipital cortex.Brain. 2013; 136: 2769-2783Crossref PubMed Scopus (0) Google Scholar]. The simple nature of these tasks may eliminate any biological advantage from improving these skills in the blind. However, the early blind demonstrate behavioral advantages for more cognitively demanding feature tasks, such as tasks including attentional measures [29.Topalidis P. et al.The role of spatial selective attention in the processing of affective prosodies in congenitally blind adults: an ERP study.Brain Res. 2020; 1739146819Crossref PubMed Scopus (5) Google Scholar,30.Lerens E. Renier L. Does visual experience influence the spatial distribution of auditory attention?.Acta Psychol. 2014; 146: 58-62Crossref PubMed Scopus (9) Google Scholar], memory components [27.Wan C.Y. et al.Early but not late-blindness leads to enhanced auditory perception.Neuropsychologia. 2010; 48: 344-348Crossref PubMed Scopus (0) Google Scholar,31.Röder B. Rösler F. Memory for environmental sounds in sighted, congenitally blind and late blind adults: evidence for cross-modal compensation.Int. J. Psychophysiol. 2003; 50: 27-39Crossref PubMed Scopus (95) Google Scholar], and acoustic frequency discrimination (Figure 1B) [18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar,25.Rokem A. Ahissar M. Interactions of cognitive and auditory abilities in congenitally blind individuals.Neuropsychologia. 2009; 47: 843-848Crossref PubMed Scopus (0) Google Scholar,27.Wan C.Y. et al.Early but not late-blindness leads to enhanced auditory perception.Neuropsychologia. 2010; 48: 344-348Crossref PubMed Scopus (0) Google Scholar,32.Arnaud L. et al.Enhanced perception of pitch changes in speech and music in early blind adults.Neuropsychologia. 2018; 117: 261-270Crossref PubMed Scopus (14) Google Scholar]. These advantages in feature processing may serve as the foundation for enhancements in high-level sensory tasks, such as speech and language.Table 1Summary of psychophysics studies investigating auditory function in the blind compared with the sightedPerformanceFeatureSpatialBehavioral taskCortical substratesBehavioral taskCortical substratesBlind > sightedDetection (frequency reaction time, temporal, speech, with spatial attention measures) [21.Muchnik C. et al.Central auditory skills in blind and sighted subjects.Scand. Audiol. 1991; 20: 19-23Crossref PubMed Google Scholar,23.Röder B. et al.Effects of interstimulus interval on auditory event-related potentials in congenitally blind and normally sighted humans.Neurosci. Lett. 1999; 264: 53-56Crossref PubMed Scopus (81) Google Scholar,25.Rokem A. Ahissar M. Interactions of cognitive and auditory abilities in congenitally blind individuals.Neuropsychologia. 2009; 47: 843-848Crossref PubMed Scopus (0) Google Scholar,29.Topalidis P. et al.The role of spatial selective attention in the processing of affective prosodies in congenitally blind adults: an ERP study.Brain Res. 2020; 1739146819Crossref PubMed Scopus (5) Google Scholar,30.Lerens E. Renier L. Does visual experience influence the spatial distribution of auditory attention?.Acta Psychol. 2014; 146: 58-62Crossref PubMed Scopus (9) Google Scholar,101.Shim H.J. et al.Influence of visual deprivation on auditory spectral resolution, temporal resolution, and speech perception.Front. Neurosci. 2019; 13: 1200Crossref PubMed Scopus (5) Google Scholar]Not examinedMAA (blind echolocators) [35.Vercillo T. et al.Enhanced auditory spatial localization in blind echolocators.Neuropsychologia. 2015; 67: 35-40Crossref PubMed Scopus (43) Google Scholar]Not examinedPeripheral localization [37.Voss P. et al.Early- and late-onset blind individuals show supra-normal auditory abilities in far-space.Curr. Biol. 2004; 14: 1734-1738Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar,38.Chen Q. et al.Spatial and nonspatial peripheral auditory processing in congenitally blind people.NeuroReport. 2006; 17: 1449-1452Crossref PubMed Scopus (16) Google Scholar,40.Röder B. et al.Improved auditory spatial tuning in blind humans.Nature. 1999; 400: 162-166Crossref PubMed Scopus (491) Google Scholar]Not examinedMonaural localization [102.Lessard N. et al.Early-blind human subjects localize sound sources better than sighted subjects.Nature. 1998; 395: 278-280Crossref PubMed Scopus (469) Google Scholar]Not examinedHorizontal (static and motion)[39.Cuppone A.V. et al.Audio-motor training enhances auditory and proprioceptive functions in the blind adult.Front. Neurosci. 2019; 13: 1272Crossref PubMed Scopus (4) Google Scholar,40.Röder B. et al.Improved auditory spatial tuning in blind humans.Nature. 1999; 400: 162-166Crossref PubMed Scopus (491) Google Scholar,47.Jiang F. et al.Auditory motion processing after early blindness.J. Vis. 2014; 14: 1-18Crossref Scopus (42) Google Scholar,48.Lewald J. Exceptional ability of blind humans to hear sound motion: implications for the emergence of auditory space.Neuropsychologia. 2013; 51: 181-186Crossref PubMed Scopus (66) Google Scholar]hMT+/V5, right lateral occipital cortex, planum temporale [47.Jiang F. et al.Auditory motion processing after early blindness.J. Vis. 2014; 14: 1-18Crossref Scopus (42) Google Scholar]Discrimination (frequency, music, vowels) [18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar,25.Rokem A. Ahissar M. Interactions of cognitive and auditory abilities in congenitally blind individuals.Neuropsychologia. 2009; 47: 843-848Crossref PubMed Scopus (0) Google Scholar,27.Wan C.Y. et al.Early but not late-blindness leads to enhanced auditory perception.Neuropsychologia. 2010; 48: 344-348Crossref PubMed Scopus (0) Google Scholar,32.Arnaud L. et al.Enhanced perception of pitch changes in speech and music in early blind adults.Neuropsychologia. 2018; 117: 261-270Crossref PubMed Scopus (14) Google Scholar]Not examinedSound categorization [52.Schepers I.M. et al.Functionally specific oscillatory activity correlates between visual and auditory cortex in the blind.Brain. 2012; 135: 922-934Crossref PubMed Scopus (29) Google Scholar]Ventral occipital temporal cortex [74.Mattioni S. et al.Categorical representation from sound and sight in the ventral occipitotemporal cortex of sighted and blind.eLife. 2020; 9: 1-33Crossref Scopus (19) Google Scholar]Feature memory [31.Röder B. Rösler F. Memory for environmental sounds in sighted, congenitally blind and late blind adults: evidence for cross-modal compensation.Int. J. Psychophysiol. 2003; 50: 27-39Crossref PubMed Scopus (95) Google Scholar]Not examinedBlind = sightedDetection (absolute auditory threshold, frequency accuracy and n-back, standard tone reaction time, episodic and semantic sound recognition) [19.Gandhi P.H. et al.A comparative study of simple auditory reaction time in blind (congenitally) and sighted subjects.Indian J. Psychol. Med. 2013; 35: 273-277Crossref PubMed Scopus (8) Google Scholar,23.Röder B. et al.Effects of interstimulus interval on auditory event-related potentials in congenitally blind and normally sighted humans.Neurosci. Lett. 1999; 264: 53-56Crossref PubMed Scopus (81) Google Scholar,58.Kärnekull S.C. et al.From perception to metacognition: auditory and olfactory functions in early blind, late blind, and sighted individuals.Front. Psychol. 2016; 7: 1-11PubMed Google Scholar,98.Anurova I. et al.Overlapping anatomical networks convey cross-modal suppression in the sighted and coactivation of "visual" and auditory cortex in the blind.Cereb. Cortex. 2019; 29: 4863-4876Crossref PubMed Scopus (2) Google Scholar]Right calcarine sulcus [98.Anurova I. et al.Overlapping anatomical networks convey cross-modal suppression in the sighted and coactivation of "visual" and auditory cortex in the blind.Cereb. Cortex. 2019; 29: 4863-4876Crossref PubMed Scopus (2) Google Scholar]Spatial direction [60.Collignon O. et al.Functional specialization for auditory-spatial processing in the occipital cortex of congenitally blind humans.Proc. Natl. Acad. Sci. U. S. A. 2011; 108: 4435-4440Crossref PubMed Scopus (0) Google Scholar]Right cuneus, right middle occipital gyrus, right superior occipital gyrus, right lingual gyrus, right middle occipito-temporal gyrus [60.Collignon O. et al.Functional specialization for auditory-spatial processing in the occipital cortex of congenitally blind humans.Proc. Natl. Acad. Sci. U. S. A. 2011; 108: 4435-4440Crossref PubMed Scopus (0) Google Scholar]MAA [33.Gori M. et al.Impairment of auditory spatial localization in congenitally blind human subjects.Brain. 2014; 137: 288-293Crossref PubMed Scopus (154) Google Scholar,35.Vercillo T. et al.Enhanced auditory spatial localization in blind echolocators.Neuropsychologia. 2015; 67: 35-40Crossref PubMed Scopus (43) Google Scholar]Not examinedTemporal bisection [20.Campus C. et al.Stronger responses in the visual cortex of sighted compared to blind individuals during auditory space representation.Sci. Rep. 2019; 9: 1935Crossref PubMed Scopus (15) Google Scholar,22.Vercillo T. et al.Early visual deprivation severely compromises the auditory sense of space in congenitally blind children.Dev. Psychol. 2016; 52: 847-853Crossref PubMed Scopus (54) Google Scholar,34.Gori M. et al.Temporal cues trick the visual and auditory cortices mimicking spatial cues in blind individuals.Hum. Brain Mapp. 2020; 41: 2077-2091Crossref PubMed Scopus (2) Google Scholar]Not examinedCentral localization [40.Röder B. et al.Improved auditory spatial tuning in blind humans.Nature. 1999; 400: 162-166Crossref PubMed Scopus (491) Google Scholar,103.Després O. et al.Spatial auditory compensation in early-blind humans: involvement of eye movements and/or attention orienting?.Neuropsychologia. 2005; 43: 1955-1962Crossref PubMed Scopus (0) Google Scholar]Not examinedFrequency discrimination with varying spatial locations [60.Collignon O. et al.Functional specialization for auditory-spatial processing in the occipital cortex of congenitally blind humans.Proc. Natl. Acad. Sci. U. S. A. 2011; 108: 4435-4440Crossref PubMed Scopus (0) Google Scholar]Not examinedHorizontal and vertical localization (static, moving with varying tone complexities, multidimensional) [44.Zwiers M.P. et al.A spatial hearing deficit in early-blind humans.J. Neurosci. 2001; 21: 1-5Crossref Google Scholar,45.Finocchietti S. et al.Encoding audio motion: spatial impairment in early blind individuals.Front. Psychol. 2015; 6: 1357Crossref PubMed Scopus (45) Google Scholar,48.Lewald J. Exceptional ability of blind humans to hear sound motion: implications for the emergence of auditory space.Neuropsychologia. 2013; 51: 181-186Crossref PubMed Scopus (66) Google Scholar,98.Anurova I. et al.Overlapping anatomical networks convey cross-modal suppression in the sighted and coactivation of "visual" and auditory cortex in the blind.Cereb. Cortex. 2019; 29: 4863-4876Crossref PubMed Scopus (2) Google Scholar,100.Poirier C. et al.Auditory motion perception activates visual motion areas in early blind subjects.NeuroImage. 2006; 31: 279-285Crossref PubMed Scopus (165) Google Scholar,102.Lessard N. et al.Early-blind human subjects localize sound sources better than sighted subjects.Nature. 1998; 395: 278-280Crossref PubMed Scopus (469) Google Scholar,103.Després O. et al.Spatial auditory compensation in early-blind humans: involvement of eye movements and/or attention orienting?.Neuropsychologia. 2005; 43: 1955-1962Crossref PubMed Scopus (0) Google Scholar]Right lateral occipital cortex [98.Anurova I. et al.Overlapping anatomical networks convey cross-modal suppression in the sighted and coactivation of "visual" and auditory cortex in the blind.Cereb. Cortex. 2019; 29: 4863-4876Crossref PubMed Scopus (2) Google Scholar], left ventral premotor cortex, V3/V3a, V1, V2 [100.Poirier C. et al.Auditory motion perception activates visual motion areas in early blind subjects.NeuroImage. 2006; 31: 279-285Crossref PubMed Scopus (165) Google Scholar]Discrimination (voice, intensity, speech, vowel, phenome, melody) [17.Trudeau-Fisette P. et al.Compensations to auditory feedback perturbations in congenitally blind and sighted speakers: acoustic and articulatory data.PLoS One. 2017; 12: 1-20Crossref Scopus (6) Google Scholar,18.Voss P. Zatorre R.J. Occipital cortical thickness predicts performance on pitch and musical tasks in blind individuals.Cereb. Cortex. 2012; 22: 2455-2465Crossref PubMed Scopus (0) Google Scholar,62.Gougoux F. et al.Voice perception in blind persons: a functional magnetic resonance imaging study.Neuropsychologia. 2009; 47: 2967-2974Crossref PubMed Scopus (0) Google Scholar,84.Fairhall S.L. et al.Plastic reorganization of neural systems for perception of others in the congenitally blind.NeuroImage. 2017; 158: 126-135Crossref PubMed Scopus (0) Google Scholar,104.Zhang L. et al.Congenital blindness enhances perception of musical rhythm more than melody in Mandarin speakers.J. Acoust. Soc. Am. 2019; 145: 354-359Crossref Scopus (3) Google Scholar]V1, extrastriate visual areas, left superior temporal sulcus, fusiform gyrus [62.Gougoux F. et al.Voice perception in blind persons: a functional magnetic resonance imaging study.Neuropsychologia. 2009; 47: 2967-2974Crossref PubMed Scopus (0) Google Scholar], bilateral fusiform face areas and the right posterior superior temporal sulcus [84.Fairhall S.L. et al.Plastic reorganization of neural systems for perception of others in the congenitally blind.NeuroImage. 2017; 158: 126-135Crossref PubMed Scopus (0) Google Scholar]Nonsemantic spatial memory [105.Setti W. et al.A novel paradigm to study spatial memory skills in blind individuals through the auditory modality.Sci. Rep. 2018; 8: 13393Crossref PubMed Scopus (10) Google Scholar]Not examinedBlind < sightedFrequency discrimination attending to the periphery [38.Chen Q. et al.Spatial and nonspatial peripheral auditory processing in congenitally blind people.NeuroReport. 2006; 17: 1449-1452Crossref PubMed Scopus (16) Google Scholar]Not examinedSpatial bisection [20.Campus C. et al.Stronger responses in the visual cortex of sighted compared to blind individuals during auditory space representation.Sci. Rep. 2019; 9: 1935Crossref PubMed Scopus (15) Google Scholar,22.Vercillo T. et al.Early visual deprivation severely compromises the auditory sense of space in congenitally blind children.Dev. Psychol. 2016; 52: 847-853Crossref PubMed Scopus (54) Google Scholar,33.Gori M. et al.Impairment of auditory spatial localization in congenitally blind human subjects.Brain. 2014; 137: 288-293Crossref PubMed Scopus (154) Google Scholar,35.Vercillo T. et al.Enhanced auditory spatial localization in blind echolocators.Neuropsychologia. 2015; 67: 35-40Crossref PubMed Scopus (43) Google Scholar]Not examinedVertical localization (static, moving, multidimensional) [42.Lewald J. Vertical sound localization in blind humans.Neuropsychologia. 2002; 40: 1868-1872Crossref PubMed Scopus (90) Google Scholar,44.Zwiers M.P. et al.A spatial hearing deficit in early-blind humans.J. Neurosci. 2001; 21: 1-5Crossref Google Scholar,45.Finocchietti S. et al.Encoding audio motion: spatial impairment in early blind individuals.Front. Psychol. 2015; 6: 1357Crossref PubMed Scopus (45) Google Scholar]Semantic spatial memory [105.Setti W. et al.A novel paradigm to study spatial memory skills in blind individuals through the auditory modality.Sci. Rep. 2018; 8: 13393Crossref PubMed Scopus (10) Google Scholar]Speed discrimination [106.Bertonati G. et al.Auditory speed processing in sighted and blind individuals.PLoS One. 2021; 16e0257676Crossref PubMed Scopus (3) Google Scholar]Distance [49.Cappagli G. et al.Auditory and proprioceptive